Electric switch with longitudinally spaced terminals and a body of conductive fluid movable relative to said terminals



J. L. GRUPEN Oct. 11, 1966 INVENTOR. M1455 www BY OF CONDUCTIVE FLUID MOVABLE RELATIVE TO SAID TERMINALS ELECTRIC SWITCH WITH LONGITUDINALLY SPACED TERMINALS AND A BODY United States Patent O ELECTRIC SWITCH WITH LONGITUDINALLY SPACED TERMINALS AND A BODY OF CON- DUCTIVE FLUID MOVABLE RELATIVE T SAID TERMINALS James L. Grupen, 1269 Lynn Way, Sunnyvale, Calif.

Filed July 1, 1964, Ser. No. 379,682 6 Claims. (Cl. 200-152) This invention relates to an electric switch in which a body of conductive lluid is moved relative to two longi- Itudinally spaced terminals and in which the lluid is maintained under pressure. The present application relates to a switch that is an improvement of the switch disclosed in Patent No. 3,142,739, issued July 28, 1964.

An object of this invention is to provide a switch, as above characterized, in which .the lluid is formed with two ring portions that are in contact, one with each terminal, with a sleeve portion of the liuid connecting the ring portions when the switch is on, and with one ring portion being separated from .the other and from said sleeve portion of the fluid when the switch is off.

This invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The above objects are realized in a switch structure that has an elongated insulating body, is provided with two longitudinally spaced switch terminals, an insulated operating stem moveable in a longitudinal bore in said body with a diametrally reduced portion of said stem forming, with the wall of the bore, an annular space in which a sleeve of conductive fluid is housed, the bore being enlarged where the same is in register with each terminal to provide rings of lluid larger diametrally than the sleeve of conductive lluid, and conductive means, using the terminals as abutments, to impose resilient pressure on said rings of liuid, both when the stem is positioned to have the sleeve of fluid between and connecting the rings of fluid and when the sleeve of lluid is displaced lby the stem to separate one ring therefrom and from the other ring of liuid.

The invention also comprises novel details of con` struction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description and which is based on the accompanying drawing. However, said drawing merely shows, and the following description merely describes, one embodiment of the present invention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in several views.

FIG. l is a longitudinal view, partly in section and partly in elevation of the present switch in on position.

FIG. 2 is a similar view of said switch in olf position.

FIG. 3 is a cross-sectional view as taken on the line 3-3 of FIG. l.

The switch .that is illustrated comprises, generally, an elongated dielectric body 5, an operating stem 6 of similar material longitudinally movable in said stem, cooperating means 7 formed in the body and stem t-o house a quantity of conductive liuid 8, longitudinally spaced terminals 9 and 10 extending preferably radially from said body, means 11, operatively associated with said terminals, for placing said conductive fluid under pressure, and boot means 12 to seal between the body 5 and stem 6 at the end-s of the former.

The body and stem are advantageously formed of ceramic material, but may be made of other suitable dielectric material. The lluid may be any conductive lluid, such as mercury or ionized gas. The boot means i12 is exemplary of sealing means at the indicated places primarily for excluding air-borne contaminants and dirt from the bearing faces of the switch parts 5 and 6.

The body 5 is provided with a longitudinal through bore 15, and the stem 6 with ends 16 that have a sliding fit in said bore. The stem is enough longer .than the body so that said ends protrude beyond both ends of the body in all operative positions in the bore 15.

The cooperating means 7 comprises, in part, longitudinally spaced enlargements 17 in the bore 15, which, together with the portion 15 of bore 15, forms the shape of a dumbbell in the bore 15 and, in part, a diametrally reduced portion 18 connecting the stem ends 16. Said portion 18, as shown, has a length approximating the overall length of the enlargements .17 and portion 15. As can be seen from FIG. l, where the stem 6 is in centered position in the body 5, so that the stem portion 18 is coextensive with the bore portions 15 and 17, the described dumbbell shape is rendered hollow or sleeve-like. The conductive fluid 8 lills said hollow shape when the stem is thus centered.

Thus, the lluid 8, in that position of the stem 6, comprises two end rings of liuid 19 and a connecting sleeve of lluid 20 smaller in diameter than the rings 19.

The terminals 9 and 10 are shown as metallic members that extend radially from the body, each in register with one of the enlargements 17. Said `terminals are shown with threaded ends 21 that extend from body portions 22 that are xedly embedded or litted into the body 5. The terminal ends may extend in the same direction, or in different relative directions, as shown.

The means 11 is shown as a piston element 23 in sliding sealing engagement with a radial bore 24 extending from each bore enlargement 17, the same being located in said radial bores inward of the body portions 22 of the terminals 9 and 10. A spring 25 in a seat formed in each body portion 22, is arranged to press against each piston element 23, thereby exerting a bias or pressure on the rings 19 of the fluid 8. Since said elements 23 exert their pressure on opposite ends of the fluid in the means 7, the entire body of such fluid is under the pressure of springs 2 The boot means 12 are shown as flexible corrugated sleeves, one end sealed around the end of the body 5 and the other end sealed over the protruding end of stem 6 on the respective end of the switch.

Operation With the stem 6 in a position, as in FIG. l, with the reduced portion 18 thereof centered between the bore enlargements 17, the conductive fluid 8 that lls the er1- largements 17 and the annular space dened between the bore portion 15 and said reduced portion 18 is maintained under pressure by the spring-biased piston elements 23. Consequently the terminals 9 and 10 are electrically connected and the switch is on With the stem 16 shifted endwise, as in FIG. 2, so that one end 16 thereof displaces part of the fluid 8 from connection with the lluid in one of the enlargements 17, thereby leaving a ring of fluid 19 in said enlargement, which is not in electrical engagement with the shifted part of the lluid, the terminals 9 and 10 become electrically separated. Therefore, the switch is off The bias of one piston element 23 is retained on the separated ring of fluid 19 and of the other piston element on the remainder of the lluid.

The above-described pressure on the fluid is present in all positions of the stem 6, at the on and off positions and all in between positions, as well. Hence the stem has a positive position which it tends to retain until moved therefrom by endwise force applied to either end of the stem.

3 The bore 15 rnay be blind at one end and the stem 6 project only from and be moved by its other end.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the construction is, of course, subject to modification without departing from the spirit and scope of the invention. Therefore, it is not desired to restrict the inventiony to the particular form of construction illust-rated and described, but to cover all modifications that may tall within the scope of the appended claims.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is:

1. An electric switch comprising:

(a) an elongated dielectric body having a longitudinal bore with two longitudinally spaced bore enlargements located inward of the body ends,

(b) an electric terminal extending from said body in register with each said bore enlargement,

(c) an elongated dielectric stem in said bore having opposite ends in sliding engagement with the bore and provided with an intermediate portion of smaller diametral size than the bore, the length of said smaller stem portion approximating the distance between the outer sides of the bore enlargements,

(d) a quantity of conductive fluid filling the bore and its enlargements around the smaller portion of the stern when said stem has its small portion centered with respect to the bore enlargements, one of the ends of the stem separating a ring of fluid in one bore enlargement from the remainder of the fluid when the stem and body are relatively shifted endwise, and

(e) means to place pressure on the opposite ends of the quantity of uid in the former position of the stem, and on the separated portions of the fluid in the latter position of the stern.

2, An electric switch according to claim 1 in which the pressure-applying means comprises spring-biased elements between the inner ends of the terminals and the conductive fluid.

3. An electric switch according to claim 1 in which the pressure-applying means comprises spring-biased elements between the inner ends ofthe terminals and the conductive fluid, said elements comprising pistons.

4. An electric switch according to claim 1 in which the body bore is a through bore, the stem has its bore-tting ends extending from the opposite ends of the body, and means is provided to seal both against leakage of fluid from the ends of the bore and to exclude air-borne contaminants from the bearing surfaces ofthe body and stem.

5. In an electric switch,

(a) a dielectric body having an elongated bore with two longitudinally spaced bore enlargements located inward of the ends of the bore,

(b) a quantity of conductive iiuid in said bore,

(c) means to place a continuously applied resilient bias on said quantity of iluid,

(d) a stem longitudinally movable in the bore to more and longitudinally separate one portion of said body from another portion thereof to form separated quantities of fluid, and

(e) a pair of longitudinally spaced electrical terminals in said body electrically connected by said fluid and electrically disconnected when one portion of said fluid is moved and separated from the other portion.

6. In an electric switch according to claim 5, the bore in the body having bore enlargements in register with the terminals, each separated portion of the fluid occupying one of said bore enlargements.

References Cited by the Examiner UNITED STATES PATENTS 1,983,150 12/1934 Sigman 200-152 ROBERT K. SCHAEFER, Primary Examiner.

KATHLEEN H. CLAFFY, Examiner.

H. HOHAUSER, Assistant Examiner. 

1. AN ELECTRIC SWITCH COMPRISING: (A) AN ELONGATED DIELECTRIC BODY HAVING A LONGITUDINAL BORE WITH TWO LONGITUDINALLY SPACED BORE ENLARGEMENTS LOCATED INWARD OF THE BODY ENDS, (B) AN ELECTRIC TERMINAL EXTENDING FROM SAID BODY IN REGISTER WITH EACH SAID BORE ENLARGEMENT, (C) AN ELONGATED DIELECTRIC STEM IN SAID BORE HAVING OPPOSITE ENDS IN SLIDING ENGAGEMENT WITH THE BORE AND PROVIDED WITH AN INTERMEDIATE PORTION OF SMALLER DIAMETRAL SIZE THAN THE BORE, THE LENGTH OF SAID SMALLER STEM PORTION APPROXIMATING THE DISTANCE BETWEEN THE OUTER SIDES OF THE BORE ENLARGEMENTS, (D) A QUANTITY OF CONDUCTIVE FLUID FILLING THE BORE AND ITS ENLARGEMENTS AROUND THE SMALLER PORTION OF THE STEM WHEN SAID STEM HAS ITS SMALL PORTION CENTERED WITH RESPECT TO THE BORE ENLARGEMENTS, ONE OF THE ENDS OF THE STEM SEPARATING A RING OF FLUID IN ONE BORE ENLARGEMENT FROM THE REMAINDER OF THE FLUID WHEN THE STEM AND BODY ARE RELATIVELY SHIFTED ENDWISE, AND (E) MEANS TO PLACE PRESSURE ON OPPOSITE ENDS OF THE QUANTITY OF FLUID IN THE FORMER POSITION OF THE STEM, AND ON THE SEPARATED PORTIONS OF THE FLUID IN THE LATTER POSITION OF THE STEM. 